As emission requirements continue to become more stringent, engine manufacturers and component suppliers continue to improve engine operation. One area that has received particular focus has been fuel injection systems. By more accurately controlling fuel injection, improved combustion can be achieved, providing better engine efficiency and reduced emissions.
One type of fuel injection system that has received much attention has been the common rail fuel system. In a common rail system, the fuel injector controls the injection of high-pressure fuel that the injector receives from a high-pressure fuel rail. The injector does not pressurize the fuel but simply controls injection by controlling the check valve.
Although common rail fuel systems provide good control of fuel injection, improvements to such systems are still necessary. Specifically, the end of a fuel injection event in a common rail fuel system often creates a pressure wave within the system. Such a pressure wave may travel through the system and affect the amount of fuel that is delivered to other fuel injectors in the system. Therefore, improper volumes of fuel may be injected into the engine.
One attempt to dampen such pressure waves in a common rail fuel system is shown in U.S. Pat. No. 6,561,165 (“the '165 patent”), issued to Hlousek on 13 May 2003. In the '165 patent, a large reservoir is contained within each fuel injector of the common rail fuel system. The reservoir is intended to help dampen any pressure waves reaching the fuel injector. However, the reservoir may have a negative influence on the starting behavior and dynamic behavior of the fuel system because it may increase the time required for changing the pressure within the fuel system.
The present invention addresses one or more of the problems set forth above.